Microwave antenna for medical ablation
First Claim
1. A microwave antenna for medical ablation, comprising:
- a transmission line having an inner conductor, an outer conductor and a dielectric insulator to provide insulation between the inner and outer conductor, and an energy emitting antenna element positioned at the distal end of the transmission line to transmit a microwave near-field;
wherein the antenna element has an inner conductor electrically coupled to the inner conductor of the transmission line, and a sheath of dielectric insulator around the inner conductor; and
wherein a conducting cap is electrically connected to the distal end of the inner conductor, and the cap surrounds a length of the sheath of insulator, and the dimensions of the cap are determined to provide impedance matching between the antenna element and the transmission line.
7 Assignments
0 Petitions
Accused Products
Abstract
A microwave antenna suitable for cardiac ablation, in particular for catheter ablation, and a method for making such an antenna. The antenna comprises a transmission line having an inner conductor, an outer conductor, and a dielectric insulator to provide insulation between the inner and outer conductors. An energy emitting antenna element is located at the distal end of the transmission line. The antenna element has an inner conductor which is electrically coupled to the inner conductor of the transmission line, and, around the inner conductor, a sheath of dielectric insulator continuous with the insulator of the transmission line. At its distal end, a hollow metallic cap is electrically connected to the inner conductor, surrounding a length of the insulator.
100 Citations
45 Claims
-
1. A microwave antenna for medical ablation, comprising:
- a transmission line having an inner conductor, an outer conductor and a dielectric insulator to provide insulation between the inner and outer conductor, and an energy emitting antenna element positioned at the distal end of the transmission line to transmit a microwave near-field;
wherein the antenna element has an inner conductor electrically coupled to the inner conductor of the transmission line, and a sheath of dielectric insulator around the inner conductor; and
wherein a conducting cap is electrically connected to the distal end of the inner conductor, and the cap surrounds a length of the sheath of insulator, and the dimensions of the cap are determined to provide impedance matching between the antenna element and the transmission line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24)
- a transmission line having an inner conductor, an outer conductor and a dielectric insulator to provide insulation between the inner and outer conductor, and an energy emitting antenna element positioned at the distal end of the transmission line to transmit a microwave near-field;
-
16. An antenna according to claim l, wherein the slot and ring sizes gradually decrease towards the tip of the antenna makes a reverse firing antenna.
-
25. A method for making a microwave antenna for medical ablation, comprising an energy emitting antenna element having an inner conductor and a surrounding sheath of insulation, in use, located at the end of a transmission line;
- wherein the method comprises the steps of;
forming a conductive cap at the distal end of the antenna element such that it surrounds a length of the sheath of insulator;
electrically coupling the conducting cap to the inner conductor of the antenna element; and
determining the dimensions of the cap to provide impedance matching between the antenna element and the transmission line. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
- wherein the method comprises the steps of;
-
45. A method of controlling the depth to width ratio of a lesion produced in tissue by the antenna of a microwave ablation device, including the steps of:
-
a) supplying microwave energy to the antenna;
b) measuring the temperature of the tissue adjacent to the antenna;
c) ceasing the supply of microwave energy to the antenna when the measured temperature reaches a first predetermined temperature; and
d) recommencing the supply of the microwave energy to the antenna when the measured temperature falls to a second predetermined temperature.
-
Specification